U.S. patent application number 14/735645 was filed with the patent office on 2015-12-17 for engine control device.
The applicant listed for this patent is Toyota Jidosha Kabushiki Kaisha. Invention is credited to Kenichi Ishii, Hiroto Miura, Hideki Ohashi, Masataka Okuda, Yosuke Yamashita.
Application Number | 20150361940 14/735645 |
Document ID | / |
Family ID | 54835768 |
Filed Date | 2015-12-17 |
United States Patent
Application |
20150361940 |
Kind Code |
A1 |
Ishii; Kenichi ; et
al. |
December 17, 2015 |
ENGINE CONTROL DEVICE
Abstract
An engine control device applied to a vehicle equipped with an
actuator for changing a suspension property of the vehicle, a
suspension control device for driving the actuator, and an engine.
The engine control device automatically stops the engine operation
when a stop condition is satisfied and automatically starts the
engine operation when a start condition is satisfied. The engine
control device continues the engine operation when a signal for
inhibiting the automatic stop of the engine operation is sent to
the engine control device in order to drive the actuator and the
engine control device judges that no malfunction occurs in the
suspension control device even if the stop condition is satisfied.
The engine control device ignores the signal and automatically
stops the engine operation when the stop condition is satisfied and
judges that the malfunction occurs in the suspension control device
even if the signal is sent to the engine control device.
Inventors: |
Ishii; Kenichi; (Miyoshi-shi
Aichi-ken, JP) ; Miura; Hiroto; (Toyota-shi
Aichi-ken, JP) ; Ohashi; Hideki; (Chiryu-shi
Aichi-ken, JP) ; Yamashita; Yosuke; (Nagoya-shi
Aichi-ken, JP) ; Okuda; Masataka; (Toyota-shi
Aichi-ken, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Toyota Jidosha Kabushiki Kaisha |
Toyota-shi Aichi-ken |
|
JP |
|
|
Family ID: |
54835768 |
Appl. No.: |
14/735645 |
Filed: |
June 10, 2015 |
Current U.S.
Class: |
701/112 |
Current CPC
Class: |
Y02T 10/48 20130101;
B60G 17/0195 20130101; B60G 2400/33 20130101; Y02T 10/40 20130101;
B60G 2400/30 20130101; B60W 10/06 20130101; F02N 11/084 20130101;
B60W 30/18018 20130101; B60W 10/22 20130101; F02N 2200/08 20130101;
B60W 2050/0295 20130101 |
International
Class: |
F02N 11/08 20060101
F02N011/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 11, 2014 |
JP |
2014-120967 |
Claims
1. An engine control device applied to a vehicle equipped with: an
electric actuator for changing a suspension property of said
vehicle; a suspension control device for driving said actuator; and
an internal combustion engine, the engine control device comprising
an engine control part programmed to: automatically stop the
operation of said engine when a predetermined engine operation stop
condition is satisfied; and automatically start the operation of
said engine when a predetermined engine operation start condition
is satisfied, wherein said engine control part is programmed to:
judge if a malfunction occurs in said suspension control device;
continue the operation of said engine when a stop inhibition
requesting signal for inhibiting the automatic stop of the
operation of said engine is sent to the engine control device in
order to drive said actuator and said engine control part judges
that no malfunction occurs in said suspension control device even
if said engine operation stop condition is satisfied; and ignore
said stop inhibition requesting signal and automatically stop the
operation of said engine when said engine operation stop condition
is satisfied and said engine control part judges that the
malfunction occurs in said suspension control device even if said
stop inhibition requesting signal is sent to the engine control
device.
2. The engine control device of claim 1, wherein said engine
control part is programmed to judge if a malfunction occurs in said
suspension control device by using said stop inhibition requesting
signal.
3. The engine control device of claim 2, wherein said suspension
control device is configured to drive said actuator for a
particular time period while continuing to send said stop
inhibition requesting signal to the engine control device during
the driving of said actuator, and said engine control part is
programmed to judge that the malfunction occurs in said suspension
control device when said suspension control device sends said stop
inhibition requesting signal to the engine control device during a
time period other than said particular time period.
4. The engine control device of claim 2, wherein said actuator
includes a motor for driving a compressor for supplying an air to
an air suspension for adjusting the height of said vehicle, said
suspension control device is configured to: start driving said
motor at a first timing when a condition for driving said motor is
satisfied; send said stop inhibition requesting signal to the
engine control device during the driving said motor; and stop
driving said motor at a second timing when a time period of driving
said motor reaches a predetermined constant time period or at a
timing before said second timing, and said engine control part is
programmed to judge that the malfunction occurs in said suspension
control device when said suspension control device continues to
send said stop inhibition requesting signal to the engine control
device for a malfunction judgment threshold time period longer than
or equal to said predetermined constant time period.
5. The engine control device of claim 1, wherein said engine
control part is programmed to continue to ignore said stop
inhibition requesting signal until a state of an ignition switch of
said vehicle is changed from an ON state to an OFF state after said
engine control part judges that the malfunction occurs in said
suspension control device.
6. The engine control device of claim 5, wherein said engine
control part is programmed to stop ignoring said stop inhibition
requesting signal when the state of said ignition switch is changed
from the ON state to the OFF state and then, to the ON state after
said engine control part judges that the malfunction occurs in said
suspension control device.
Description
BACKGROUND ART
[0001] 1. Field of the invention
[0002] The invention relates to an engine control device applied to
a vehicle comprising a suspension control device and an internal
combustion engine and capable to automatically stop an operation of
the engine and automatically start the operation of the engine
(restart the operation of the engine).
[0003] 2. Description of Related Art
[0004] Conventionally, a suspension control device is known. The
suspension control device electrically controls a suspension
property of a vehicle such as a vehicle height, a spring constant
of a suspension and a damping force of a shock absorber. The
suspension control device includes an actuator. The actuator is,
for example, a motor for driving a compressor for supplying an air
to an air suspension for adjusting the vehicle height. An
electricity consumption of such a motor is large and thus, a
battery voltage (a power source voltage) of the vehicle excessively
lowers when the motor is driven, and as a result, a problem may
occur in another electric devices.
[0005] Accordingly, one of the conventional techniques carries out
an idle-up of the engine when the operation of the engine is under
the idling state in order to drive the actuator (for example, the
motor) of the suspension control device which consumes a large
amount of the power (for example, refer to JP 59-117511 U).
Thereby, when the actuator of the suspension control device is
driven under the idling state of the engine, the amount of the
power generated by an alternator (an electric generator) driven by
the engine increases. As a result, the voltage of the battery of
the vehicle does not excessively lower and the actuator can be
assuredly driven.
[0006] On the other hand, in recent years, a device for improving
the fuel consumption of the engine by automatically stopping the
operation of the engine when a predetermined engine operation stop
condition is satisfied (that is, the automatic stop and start
control device of the engine) has been employed (for example, refer
to JP 2006-329122 A and JP 2013-36343 A). Hereinafter, the
automatic stop and start control device of the engine may be simply
referred to as "the engine control device".
SUMMARY OF THE INVENTION
[0007] As described above, when the actuator of the suspension
control device is driven, the battery voltage lowers and thus, it
is desired that the operation of the engine continues so as to make
the alternator generate the power even when the engine operation
stop condition is satisfied. Accordingly, the inventors of this
application has realized that it is preferred to send a signal for
requesting to inhibit the automatic stop of the operation of the
engine to the engine control device when the suspension control
device drives the actuator and the engine control device continues
the operation of the engine when the engine control device receives
the signal. Hereinafter, the signal for requesting to inhibit the
automatic stop of the engine operation may be referred to as "the
engine operation stop inhibition requesting signal" or "the stop
inhibition requesting signal".
[0008] However, when the suspension control device continues to
generate the stop inhibition requesting signal due to any reason
(for example, due to a malfunction occurring in the CPU), the
engine control device cannot stop the operation of the engine even
when the engine operation stop condition is satisfied and thus, the
problem such as the increasing of the fuel consumption of the
engine occurs.
[0009] The invention is made for solving the problem described
above. That is, one of the objects of the invention is to provide
an engine control device which can stop the operation of the engine
when the engine operation stop condition is satisfied even if the
suspension control device continues to generate the stop inhibition
requesting signal due to the malfunction of the suspension control
device.
[0010] The engine control device according to the invention for
accomplishing the object described above is applied to a vehicle
equipped with:
[0011] an electric actuator for changing a suspension property of
the vehicle;
[0012] a suspension control device for driving the actuator;
and
[0013] an internal combustion engine.
[0014] Hereinafter, the engine control device according to the
invention may be referred to as "the invention device"
[0015] Further, the invention device comprises an engine control
part programmed to:
[0016] automatically stop the operation of the engine when a
predetermined engine operation stop condition is satisfied; and
[0017] automatically start the operation of the engine when a
predetermined engine operation start condition is satisfied.
[0018] In addition, the engine control part is programmed to judge
if a malfunction occurs in the suspension control device.
[0019] The engine control part is programmed to continue the
operation of the engine (that is, not to carry out the automatic
stop of the operation of the engine) when a stop inhibition
requesting signal for inhibiting the automatic stop of the
operation of the engine is sent to the engine control device in
order to drive the actuator and the engine control part judges that
no malfunction occurs in the suspension control device even if the
engine operation stop condition is satisfied.
[0020] On the other hand, the engine control part is programmed to
ignore (mask) the stop inhibition requesting signal and
automatically stop the operation of the engine when the engine
operation stop condition is satisfied and the engine control part
judges that the malfunction occurs in the suspension control device
even if the stop inhibition requesting signal is sent to the engine
control device.
[0021] Basically, the invention device continues to operate the
engine when the suspension control device sends the stop inhibition
requesting signal to the invention device and thus, the power
source voltage does not excessively lower even when the actuator
described above is driven. Thereby, no trouble occurs in the other
system of the vehicle. However, when the malfunction occurs in the
suspension control device and thus, the suspension control device
continues to send the stop inhibition requesting signal to the
invention device, the invention device ignores (masks) the stop
inhibition requesting signal and thus, the invention device can
automatically stop the operation of the engine. As a result, the
situation where the vehicle continues to run with an increased
consumption of the fuel of the engine can be avoided and thus, the
increasing of the consumption of the fuel can be prevented.
[0022] In this case, preferably, the engine control part may be
programmed to judge if a malfunction occurs in the suspension
control device by using the stop inhibition requesting signal.
[0023] Thereby, the invention device can judge that the malfunction
occurs in the suspension control device without carrying out an
exchange of a specific signal other than the stop inhibition
requesting signal between the suspension control device and the
invention device (the engine control device).
[0024] Further, the suspension control device does not need to
always drive the actuator. That is, the suspension control device
may be configured to drive the actuator during a particular time
period (that is, during a time period when the driving of the
actuator is allowed or during a part of the time period) and send
the stop inhibition requesting signal to the engine control device
while the suspension control device drives the actuator. In this
case, if the suspension control device is under the normal state,
the suspension control device does not send the stop inhibition
requesting signal to the engine control device during a time period
other than the particular time period.
[0025] Accordingly, the engine control part may be programmed to
judge that the malfunction occurs in the suspension control device
when the suspension control device sends the stop inhibition
requesting signal to the engine control part during a time period
other than the particular time period. Thereby, the engine control
part can easily judge if a malfunction occurs in the suspension
control device.
[0026] In particular, the actuator may include a motor for driving
a compressor for supplying an air to an air suspension for
adjusting the height of the vehicle.
[0027] In this case, the suspension control device may be congirued
to:
[0028] start driving the motor at a first timing when a condition
for driving the motor is satisfied;
[0029] send the stop inhibition requesting signal to the present
device (the engine control device) during the driving the motor;
and
[0030] stop driving the motor at a second timing when a time period
of driving the motor reaches a predetermined constant time period
or at a timing before the second timing.
[0031] In other words, the motor and the compressor may be
configured to complete the vehicle height adjustment before the
time period of driving the motor to drive the compressor reaches
the predetermined constant time period.
[0032] If the suspension control device is configured as described
above, the engine control part may be configured to judge that the
malfunction occurs in the suspension control device when the
suspension control device has continued to send the stop inhibit
requesting signal to the engine control device (the invention
device) for a malfunction judgment threshold time period longer
than or equal to the predetermined constant time period.
[0033] Thereby, when the suspension control device is under the
normal state, the suspension control device has not continued to
send the stop inhibition requesting signal to the engine control
device for the malfunction judgment threshold time period. Thus,
the engine control device can easily and assuredly judge if a
malfunction occurs in the suspension control device.
[0034] The engine control part of the invention device may be
programmed to continue to ignore (mask) the stop inhibition
requesting signal until a state of an ignition switch of the
vehicle is changed from an ON state to an OFF state after the
engine control part judges that the malfunction occurs in the
suspension control device.
[0035] Thereby, when the ignition switch is under the ON state and
it is judged that the malfunction occurs in the suspension control
device, the stop inhibition requesting signal is continued to be
ignored until the state of the ignition switch is changed to the
OFF state. Thus, the occasion of automatically stopping the
operation of the engine increases. That is, once it is judged that
the malfunction occurs in the suspension control device when the
ignition switch is under the ON state, the suspension control
device is not repaired or replaced at least until the driving of
the vehicle is terminated. Thereby, it can be expected that the
suspension control device is continued to be under the malfunction
state until the state of the ignition switch is changed to the OFF
state. Therefore, according to the invention device having the
configuration described above, the occasions of automatically
stopping the operation of the engine can be effectively utilized
independently of the error stop inhibition requesting signal.
Alternatively, according to the present device having the
configuration described above, the automatic stop of the operation
of the engine can be carried out without judging if the malfunction
judgment threshold time period elapses in order to judge if a
malfunction occurs in the suspension control device every the stop
inhibition requesting signal is sent. Thus, the shortening of the
time period when the operation of the engine is stopped can be
prevented. Thereby, the increasing of the fuel consumption can be
prevented.
[0036] In this case, the engine control part may be programmed to
stop ignoring the stop inhibition requesting signal when the state
of the ignition switch of the vehicle is changed from the ON state
to the OFF state and then, to the ON state again after the engine
control part judges that the malfunction occurs in the suspension
control device.
[0037] After the state of the ignition switch is changed to the OFF
state, the suspension control device may be repaired or replaced
until the state of the ignition switch is changed to the ON state
next time. Therefore, when the state of the ignition switch is
again changed to the ON state, it is desired that it is judged if a
malfunction occurs in the suspension control device again. Thereby,
the user can efficiently use the function of the suspension control
device.
[0038] The other objects, the other features and the accompanying
advantages of the invention can be easily understood from the
description of the embodiments of the invention with reference to
the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a schematic configuration diagram of a vehicle
equipped with an engine control device according to the embodiment
of the invention.
[0040] FIG. 2 is a flow chart showing a summary of the processes
executed by a CPU of the engine control device shown in FIG. 1.
[0041] FIG. 3 is a flow chart showing a vehicle height control
routine executed by a CPU of a suspension control device shown in
FIG. 1.
[0042] FIG. 4 is a flow chart showing a stop inhibition requesting
signal sending and motor driving limiting routine executed by the
CPU of the suspension control device shown in FIG. 1.
[0043] FIG. 5 is a flow chart showing a mask resetting routine
executed by a CPU of the engine control device shown in FIG. 1.
[0044] FIG. 6 is a flow chart showing a mask setting routine
executed by the CPU of the engine control device shown in FIG.
1.
[0045] FIG. 7 is a flow chart showing an automatic engine operation
stopping routine executed by the CPU of the engine control device
shown in FIG. 1.
[0046] FIG. 8 is a flow chart showing an automatic engine operation
start routine executed by the CPU of the engine control device
shown in FIG. 1.
[0047] FIG. 9 is a flow chart showing a mask setting routine
executed by the CPU of the engine control device according to a
modification of the embodiment of the invention.
DESCRIPTION OF THE EMBODIMENTS
<Configuration>
[0048] FIG. 1 shows a general configuration of a vehicle 10
equipped with an engine control device according to an embodiment
of the invention. The vehicle 10 is equipped with an internal
combustion engine 20, engine actuators 25, an engine control device
30, a suspension device 40, a suspension control device 50,
etc.
[0049] The engine 20 is a four-cycle spark-ignition multi-cylinder
gasoline-fuel internal combustion engine. The engine 20 is
configured to generate a torque for driving drive wheels (not
shown) of the vehicle 10. Further, the engine 20 is configured to
drive an alternator (an electric generator) 21 during the engine
operation and generate an electric power by the alternator 21. The
engine actuators 25 include well-known actuators for carrying out
operations necessary to operate the engine 20. For example, the
engine actuators include fuel injectors, ignition devices and a
throttle actuator for changing an opening degree of a throttle
valve.
[0050] The engine control device 30 includes an electronic control
circuit having the well-known micro computer including the CPU, the
ROM, the RAM, the backup RAM, the interface provided with the AD
converter, etc. The ROM stores programs (instructions) executed by
the CPU. Hereinafter, the engine control device 30 will be referred
to as "the engine ECU" and may be written by "the EG/ECU". The ECU
means the Electronic Control Unit. Further, the engine control
device 30 may be referred to as "the automatic stop/start control
device of the engine (S&S/ECU: Start and Stop ECU)".
[0051] The engine control device 30 is configured to acquire
various input values from a plurality of engine operation state
amount sensors 31. The engine operation state amount sensors 31
include sensors and a switch described below. [0052] An engine
speed sensor for detecting the engine speed NE. [0053] A throttle
valve opening degree sensor for detecting an opening degree TA of
the throttle valve not shown. [0054] An acceleration pedal
manipulation amount sensor for detecting a manipulation amount AP
of the acceleration pedal not shown. [0055] An air flow meter for
detecting an intake air amount Ga of the engine. [0056] A break
switch (a stop lamp switch) for detecting a depression of the break
pedal not shown.
[0057] Further, the engine control device 30 is configured to
receive a signal from the ignition switch 32 of the engine 10 and
acquire a state (ON and OFF states) of the ignition switch 32.
[0058] The engine control device 30 is connected to the suspension
control device 50 via an onboard network (CAN) so as to enable an
information exchange (a communication) with the suspension control
device 50. Further, the engine control device 30 is connected to
the engine actuators 25 and is configured to send driving signals
to the engine actuators 25, respectively. That is, the engine
control device 30 is configured to send ignition command signals to
the ignition plugs (actually, the igniters) of the cylinders,
respectively, send injection command signals to the fuel injectors
of the cylinders, respectively, and send an opening degree command
signal to the throttle actuator.
[0059] The suspension device 40 is the well-known air suspension
device having a damping force variable function and includes
devices, parts, etc. described below. [0060] A right front side
suspension device 41. [0061] A left front side suspension device
42. [0062] A right rear side suspension device 43. [0063] A left
rear side suspension device 44. [0064] A compressor/motor device
45. [0065] A front vehicle height adjustment valve device 46.
[0066] A rear vehicle height adjustment valve device 47. [0067] An
exhaust valve 48.
[0068] The right front side suspension device 41 has a chamber 41a
including a diaphragm, a shock absorber 41b and an absorber control
actuator 41c. Hereinafter, the absorber control actuator 41c may be
written by "the ACA".
[0069] When a compressed air is supplied to the chamber 41a via an
air delivery pipes P and PFr, the distance between the right front
wheel and the vehicle body is increased and thus, the vehicle
height of the vehicle body part at the right front wheel area is
raised. When the air is discharged from the chamber 41a, the
distance between the right front wheel and the corresponding
vehicle body is decreased and thus, the vehicle height of the
vehicle body part at the right front wheel area is lowered.
[0070] The shock absorber 41b includes a rotory valve (not shown)
for changing the damping force with multistep (in this embodiment,
sixteen steps). Hereinafter, the rotary valve may be referred to as
"the damping force control valve".
[0071] The ACA 41c is a step motor and rotates the rotary valve to
change the damping force generated by the shock absorber 41b.
[0072] The left front side, right rear side and left rear side
suspension devices 42, 43 and 44 have the same configuration as the
configuration of the right front side suspension device 41,
respectively and thus, the descriptions thereof will be omitted. It
should be noted that the elements 42a, 43a and 44a are chambers
corresponding to the chamber 41a, respectively. Further, the
elements 42b, 43b and 44b are shock absorbers corresponding to the
shock absorber 41b, respectively. Furthermore, the elements 42c,
43c and 44c are ACAs corresponding to the ACA 41c,
respectively.
[0073] The compressor/motor device 45 includes a motor (an electric
motor) 45a, a compressor 45b and a check valve 45c.
[0074] The motor 45a is one of the electrically driven actuators
for changing a suspension property (the vehicle height) of the
vehicle body according to the invention. The motor 45a drives the
compressor 45b. The motor 45a is controlled by the suspension
control device 50.
[0075] When the compressor 45b is driven, the compressor 45b
compresses the air and supplies the compressed air to the air
delivery pipe P.
[0076] The check valve 45c allows the air to flow from the
compressor 45b to the air delivery pipe P and prevents the air from
flowing from the air delivery pipe P to the compressor 45b.
[0077] The front vehicle height adjustment valve device 46 has a
right front side and left front side control valves 46R and
46L.
[0078] The right front side control valve 46R is a two position
electromagnetic valve which can be positioned selectively at one of
communication and shut-off positions.
[0079] When the right front side control valve 46R is positioned at
the communication position, the air delivery pipe P and the air
delivery pipe PFr communicate with each other. Therefore, the air
delivery pipe P and the chamber 41a communicate with each
other.
[0080] On the other hand, when the right front side control valve
46R is positioned at the shut-off position, the communication of
the air delivery pipes P and PFr with each other is shut off.
Therefore, the communication of the delivery pipe P and the chamber
41a with each other is shut off.
[0081] The left front side control valve 46L has the same
configuration and function as the configuration and the function of
the right front side control valve 46R.
[0082] Therefore, when the left front side control valve 46L is
positioned at the communication position, the air delivery pipe P
and the chamber 42a communicate with each other.
[0083] On the other hand, when the left front side control valve
46L is positioned at the shut-off position, the communication of
the air delivery pipe P and the chamber 42a with each other is shut
off.
[0084] The rear vehicle height adjustment device 47 has a right
rear side and left rear side control valves 47R and 47L.
[0085] The right rear side control valve 47R has the same
configuration and function as the configuration and function of the
right front side control valve 46R.
[0086] Therefore, when the right rear side control valve 47R is
positioned at the communication position, the air delivery pipe P
and the chamber 43a communicate with each other.
[0087] On the other hand, when the right rear side control valve
47R is positioned at the shut-off position, the communication of
the air delivery pipe P and the chamber 43a with each other is shut
off.
[0088] The left rear side control valve 47L has the same
configuration and function as the configuration and function of the
right front side control valve 46R.
[0089] Therefore, when the left rear side control valve 47L is
positioned at the communication position, the air delivery pipe P
and the chamber 44a communicate with each other.
[0090] On the other hand, when the rear left control valve 47L is
positioned at the shut-off position, the communication of the air
delivery pipe P and the chamber 44a with each other is shut
off.
[0091] The exhaust valve 48 is a two position electromagnetic valve
which can be positioned selectively at one of communication and
shut-off positions.
[0092] When the exhaust valve 48 is positioned at the communication
position, the air delivery pipe P opens to the outside air.
[0093] On the other hand, when the exhaust valve 48 is positioned
at the shut-off position, the air delivery pipe P does not open to
the outside air.
[0094] The suspension control device 50 includes an electronic
control circuit including the micro computer similar to the micro
computer of the engine control device 30. Hereinafter, the
suspension control device 50 may be referred to as "the vehicle
height adjustment control device" or "the suspension ECU" or "the
absorber control unit" and may be written by "the SP/ECU".
[0095] The suspension control device 50 is configured to receive
signals from the ignition switch 32, the vehicle speed sensor 33
for detecting the vehicle speed SPD and an user switch (a
change-over switch) 34.
[0096] The user switch 34 is a switch manipulated by an user when
the user selects the vehicle height and/or the damping force which
the user desires. The user can select and instruct any of the
vehicle height raising and lowering by manipulating the user switch
34. Further, the user can select and instruct the damping forces of
the shock absorbers 41b to 44b corresponding to the wheels,
respectively at any of the hard, normal and soft modes by
manipulating the user switch 34.
[0097] Furthermore, the suspension control device 50 is configured
to acquire input values from a plurality of sensors for detecting
suspension state amounts described below, respectively. [0098] A
vehicle height sensor 51 for detecting the vehicle height and the
vertical direction acceleration of the right front wheel area
vehicle body part (at the front right side). [0099] A vehicle
height sensor 52 for detecting the vehicle height and the vertical
direction acceleration of the left front wheel area vehicle body
part (at the front left side). [0100] A vehicle height sensor 53
for detecting the vehicle height and the vertical direction
acceleration of the right rear wheel area vehicle body part (at the
rear right side). [0101] A vehicle height sensor 54 for detecting
the vehicle height and the vertical direction acceleration of the
left rear wheel area vehicle body part (at the rear left side).
[0102] That is, each of the vehicle height sensors 51 to 54
incorporates a G sensor for detecting the acceleration in the
vertical direction of a predetermined part of the vehicle body.
[0103] In addition, the suspension control device 50 is connected
to the other sensors 35 and is configured to acquire various input
values from the sensors 35. The sensors 35 include a yaw rate
sensor, a steering angle sensor, etc.
[0104] The suspension control device 50 is connected to the
electric actuators of the suspension device 40 (that is, the ACAs
41c to 44c, the compressor driving motor 45a, the control valves
46R, 46L, 47R and 47L, the exhaust valve 48, etc.). The suspension
control device 50 is configured to send the driving signals to the
actuators, respectively to drive (control) the actuators.
[0105] For example, the suspension control device 50 drives the
motor 45a and moves the right front side control valve 46R to the
communication position while moving the exhaust valve 48 to the
shut-off position to raise the vehicle height of the right front
wheel area vehicle body part. Thereby, the air compressed by the
compressor 45b is supplied to the chamber 41a through the air
delivery pipe P, the right front side control valve 46R and the air
delivery pipe PFr. As a result, the vehicle height of the right
front wheel area vehicle body part is raised. Then, the suspension
control device 50 moves the right front side control valve 46R to
the shut-off position. As as result, the vehicle height of the
right front wheel area vehicle body part is maintained.
[0106] On the other hand, the suspension control device 50 stops
the operation of the motor 45a and moves the right front side
control valve 46R to the communication position while moving the
exhaust valve 48 to the communication position to lower the vehicle
height of the right front wheel area vehicle body part. Thereby,
the air in the chamber 41ais discharged to the outside air through
the air delivery pipe PFr, the right front side control valve 46R,
the air delivery pipe P and the exhaust valve 48. As a result, the
vehicle height of the right front wheel area vehicle body part is
lowered. Then, the suspension control device 50 moves the right
front side control valve 46R to the shut-off position. As a result,
the vehicle height of the right-front wheel vehicle body is
maintained.
[0107] Similarly, the motor 45a, the left front side control valve
46L and the exhaust valve 48 are used to adjust the vehicle height
of the left front wheel area vehicle body part. The motor 45a, the
right rear side control valve 47R and the exhaust valve 48 are used
to adjust the vehicle height of the right rear wheel area vehicle
body part. The motor 45a, the left rear side control valve 47L and
the exhaust valve 48 are used to adjust the vehicle height of the
left rear wheel area vehicle body part. The method for controlling
the adjustment of the vehicle height of each of the vehicle body
parts is similar to the method for controlling the adjustment of
the vehicle height of the right front wheel area vehicle body part
described above and thus, the descriptions thereof will be
omitted.
[0108] Further, the suspension control device 50 calculates an
optimal damping force at each of the wheels on the basis of the
received various sensor signals, etc. Then, the suspension control
device 50 changes the step position of each of the absorber control
actuators (the ACAs) 41c to 44c such that the damping force of each
of the shock absorbers 41b to 44b of the wheels corresponds to the
calculated optimal damping force.
[0109] Further, the vehicle 10 incorporates a battery 70 for
accessories of the vehicle 10. The battery 70 is electrically
connected to the alternator 21 (and actually, a voltage regulator
not shown) and is configured to be charged by the power generated
by the alternator 21. The battery 70 is connected to the engine
control device 30 and the suspension control device 50 by power
lines L, respectively and functions as a power source for the
devices 30 and 50 (supplies the power to the devices 30 and 50).
Further, the battery 70 functions as the power source for supplying
the power to the engine actuators 25 and the actuators described
above of the suspension device 40 to drive the engine actuators 25
and the actuators of the suspension device 40.
<Summary of Actuation of Engine Control Device>
[0110] Next, the summary of the actuation of the engine control
device (the EG/ECU) 30 configured as described above will be
described. The CPU of the engine control device 30 is programmed to
execute a routine shown in FIG. 2 by a summarized flow chart every
a predetermined time period elapses. Hereinafter, the CPU of the
engine control device 30 will be written by "the EG/CPU".
[0111] Therefore, the EG/CPU starts the processes from the step 200
of FIG. 2 at a predetermined timing and then, proceeds to the step
210 where the EG/CPU judges if the engine 20 is being operated.
When the engine 20 is not operated at the process of the step 210
being executed, the EG/CPU judges "No" at the step 210 and then,
proceeds directly to the step 295 where the EG/CPU terminates the
routine.
[0112] On the other hand, when the engine 20 is being operated at
the process of the step 210 being executed, the EG/CPU judges "Yes"
at the step 210 and then, proceeds to the step 220 where the EG/CPU
judges if the engine operation stop condition (the condition for
temporarily stopping the operation of the engine 20) is satisfied.
For example, the engine operation stop condition is satisfied when
all conditions described below are satisfied.
[0113] (Condition 1) The vehicle speed SPD is smaller than or equal
to a threshold vehicle speed for the engine operation stop SPDth.
The threshold vehicle speed for the engine operation stop SPDth is
a predetermined low vehicle speed and in this embodiment, is zero
(km/h).
[0114] (Condition 2) The brake switch is under the ON state. That
is, the brake pedal is depressed and the vehicle 10 is being
braked.
[0115] (Condition 3) The acceleration pedal manipulation amount AP
is zero. That is, the acceleration pedal is not depressed and thus,
no acceleration is requested.
[0116] However, the engine operation stop condition is not limited
to the conditions described above. For example, the condition that
the battery voltage VB is higher than or equal to a predetermined
threshold voltage VBth and/or the condition that the cooling water
temperature THW is higher than or equal to a predetermined
threshold cooling water temperature THWth, etc. may be added to the
conditions 1 to 3 described above.
[0117] When the engine operation stop condition is not satisfied at
the process of the step 220 being executed, the EG/CPU judges "No"
at the step 220 and then, proceeds directly to the step 250 where
the EG/CPU continues to operate the engine 20. Then, the EG/CPU
proceeds to the step 295 where the EG/CPU terminates the
routine.
[0118] On the other hand, when the engine operation stop condition
is satisfied at the process of the step 220 being executed, the
EG/CPU judges "Yes" at the step 220 and then, proceeds to the step
230 where the EG/CPU judges if the suspension control device (the
SP/ECU) 50 sends a signal for requesting to inhibit the stop of the
engine operation (the stop inhibition requesting signal) to the
EG/ECU 30.
[0119] The SP/ECU 50 is configured to send the signal for
requesting to inhibit the stop of the engine operation (that is,
the stop inhibition requesting signal) to the EG/ECU 30 to prevent
the battery voltage VB from lowering excessively when the SP/ECU 50
drives the predetermined actuators of the suspension device 40. The
predetermined actuators are electric actuators for changing the
suspension property, respectively, each of which consumes a large
amount of the power or needs a large value of the electric source
voltage for ensuring the operation of the actuator. That is, for
example, the predetermined actuators include the motor 45a for
driving the compressor 45b and/or the absober control actuators
(the ACAs) 41c to 44c which are step motors, respectively.
[0120] Further, the SP/ECU 50 is configured not to continue to
drive the motor 45a beyond a constant threshold driving time period
Tth when the SP/ECU 50 carries out the adjustment of the vehicle
height. This is because the adjustment of the vehicle height can be
deemed to be completed when the motor 45a has continued to be
driven for the threshold driving time period Tth. Therefore, when
the SP/ECU 50 is under the normal state, the SP/ECU 50 is
configured not to continue to send the stop inhibition requesting
signal to the EG/ECU 30 beyond the threshold driving time period
Tth when the SP/ECU carries out the adjustment of the vehicle
height.
[0121] When the SP/ECU 50 does not send the stop inhibition
requesting signal to the EG/ECU 30 at the process of the step 230
being executed, the EG/CPU judges "No" at the step 230 and then,
proceeds to the step 260 where the EG/CPU stops (automatically
stops) the operation of the engine 20, for example, by stopping the
fuel injections. Then, the EG/CPU proceeds to the step 295 where
the EG/CPU terminates the routine.
[0122] On the other hand, when the SP/ECU 50 sends the stop
inhibition requesting signal to the EG/ECU 30 at the process of the
step 230 being executed, the EG/CPU judges "Yes" at the step 230
and then, proceeds to the step 240 where the EG/CPU judges if a
malfunction occurs in the SP/ECU 50.
[0123] As described above, when the SP/ECU 50 is under the normal
state, the SP/ECU 50 is configured not to continue to send the stop
inhibition requesting signal to the EG/ECU 30 beyond the threshold
driving time period Tth. Accordingly, the EG/CPU judges if a
malfunction occurs in the SP/ECU 50 by judging if the SP/ECU 50 has
continued to send the stop inhibition requesting signal to the
EG/ECU 30 beyond a predetermined time period Tth+.alpha. (.alpha.
is larger than or equal to zero). However, the method for judging
if a malfunction occurs in the SP/ECU 50 at the step 240 is not
limited to the method described above. Hereinafter, the
predetermined time period Tth+.alpha. may be referred to as "the
malfunction judgment threshold time period Tijoth".
[0124] When the time period for the SP/ECU 50 continuing to send
the stop inhibition requesting signal to the EG/ECU 30, is shorter
than the malfunction judgment threshold time period Tijoth and
thus, the EG/CPU judges that no malfunction occurs in the SP/ECU 50
at the step 240, the EG/CPU proceeds to the step 250. That is, when
the EG/CPU judges that no malfunction occurs in the SP/ECU 50 (in
other words, the EG/CPU judges that the SP/ECU 50 is under the
normal state), the EG/CPU proceeds to the step 250 where the EG/CPU
continues to operate the engine 20 and then, proceeds to the step
295. As a result, even when the engine operation stop condition is
satisfied, the operation of the engine 20 is not stopped.
[0125] On the other hand, when the SP/ECU 50 has continued to send
the stop inhibition requesting signal to the EG/ECU 30 beyond the
malfunction judgment threshold time period Tijoth (=Tth+.alpha.)
and thus, the EG/CPU judges that a malfunction occurs in the SP/ECU
50 at the step 240, the EG/CPU proceeds to the step 260 where the
EG/CPU stops the operation of the engine 20. That is, even when the
SP/ECU 50 generates the stop inhibition requesting signal, the
EG/ECU 30 deems that the stop inhibition requesting signal is
generated (sent) due to the malfunction of the SP/ECU 50 and then,
the EG/ECU 30 stops the operation of the engine 20 while ignoring
(masking) the stop inhibition requesting signal. Then, the EG/CPU
proceeds to the step 295 where the EG/CPU terminates the routine.
The summary of the actuation of the engine control device 30
relating to the invention was described.
<Actual Actuation>
[0126] Next, the concrete actuations of the engine control unit
(the EG/ECU) 30 and the suspension control device (the SP/ECU) 50
will be described.
1. Actuation of SP/ECU
(1) Adjustment of Vehicle Height
[0127] The CPU of the SP/ECU 50 is programmed to execute a vehicle
height control routine shown in FIG. 3 by a flow chart every a
predetermined time period elapses. Hereinafter, the CPU of the
SP/ECU 50 will be written by "the SP/CPU". Therefore, the SP/CPU
starts the processes from the step 300 of FIG. 3 at a predetermined
timing and then, proceeds to the step 305 where the SP/CPU judges
if a value of a vehicle height adjustment stop flag Xteishi is
"0".
[0128] The value "0" is set to the value of the flag Xteishi in an
initial routine executed when the state of the ignition switch 32
is changed from the ON state to the OFF state. Further, the value
"1" is set to the value of the flag Xteishi in a motor driving
limiting routine shown in FIG. 4 described below. When the value of
the flag Xteishi is "1" at the process of the step 305 being
executed, the SP/CPU judges "No" at the step 305 and then, proceeds
directly to the step 395 where the SP/CPU terminates the
routine.
[0129] On the other hand, when the value of the flag Xteishi is "0"
at the process of the step 305 being executed, the SP/CPU judges
taht "Yes" at the step 305 and then, proceeds to the step 310 where
the SP/CPU judges if the vehicle height adjustment is
completed.
[0130] Now, it is assumed that the vehicle height adjustment is
completed. In this case, the SP/CPU judges "Yes" at the step 310
and then, proceeds to the step 315 where the SP/CPU judges if the
vehicle height adjustment is requested by the user manipulating the
user switch 34.
[0131] When the vehicle height adjustment is requested by the user,
the SP/CPU judges "Yes" at the step 315 and then, proceeds to the
step 320 where the SP/CPU judges if a condition for allowing to
change a target vehicle height (a target vehicle height change
allowance condition, that is, a vehicle height adjustment execution
condition) is satisfied. For example, this condition includes facts
that the engine 20 is being operated, the vehicle speed SPD does
not decrease below a low vehicle speed SPDLth (for example, 60
km/h) after the vehicle speed SPD exceeds a high vehicle speed
SPDHth (for example, 80 km/h), the battery voltage VB is larger
than or equal to the predetermined threshold voltage VBth, etc.
[0132] When the target vehicle height change allowance condition is
satisfied at the process of the step 320 being executed, the SP/CPU
judges "Yes" at the step 320 and then, proceeds to the step 325
where the SP/CPU determines a target value of the vehicle height of
each of the vehicle body parts at the wheels (that is, a target
value of each of the vehicle heights of the right front wheel area
vehicle body part, the left front wheel area vehicle body part, the
right rear wheel area vehicle body part and the left front wheel
area vehicle body part and hereinafter, these vehicle heights will
be referred to as "the wheel area vehicle height", respectively) on
the basis of each of the present wheel area vehicle heights and the
manipulation state of the user switch 34. Hereinafter, the target
value of the vehicle height of each of the vehicle body parts at
the wheels will be referred to as "the target wheel area vehicle
height", respectively. For example, when all of the present wheel
area vehicle heights are vehicle heights corresponding to "low",
respectively and the manipulation state of the user switch 34
requests to raise the vehicle height, the vehicle heights
corresponding to "neutral (or high)" are set as the target wheel
area vehicle heights, respectively.
[0133] Next, the SP/CPU proceeds to the step 330 where the SP/CPU
judges if any of the actual wheel area vehicle heights is not
within a range between a value VHL and a value VHU. The value VHL
corresponds to a value obtained by subtracting a predetermined
positive value y from the target wheel area vehicle height VHtgt
(VHL=VHtgt-y). The value VHU corresponds to a value obtained by
adding the predetermined positive value .gamma. to the target wheel
area vehicle height VHtgt (VHU=VHtgt+.gamma.). In other words, at
the step 330, the SP/CPU judges if any of the suspension devices 41
to 44 does not complete the adjustment of the corresponding wheel
area vehicle height.
[0134] When any of the suspension devices 41 to 44 does not
complete the adjustment of the corresponding wheel area vehicle
height at the process of the step 330 being executed, the SP/CPU
judges "Yes" at the step 330 and then, executes the processes of
the steps 335 and 340 as described below in sequence. Then, the
SP/CPU proceeds to the step 395 where the SP/CPU terminates the
routine.
[0135] Step 335: The SP/CPU controls the compressor driving motor
45a. At this time, when it is necessary to raise any of the wheel
area vehicle heights by any of the suspension devices 41 to 44, the
SP/CPU drives the compressor driving motor 45a.
[0136] On the other hand, when it is necessary to lower any of the
wheel area vehicle heights by any of the suspension devices 41 to
44, the SP/CPU stops driving the compressor driving motor 45a.
[0137] It should be noted that before the SP/CPU starts driving the
motor 45a at the step 335, the SP/CPU starts sending the stop
inhibition requesting signal to the EG/ECU 30 through the onboard
network CAN. Hereinafter, the timing when the SP/CPU starts driving
the motor 45a may be referred to as "the first timing when the
condition of driving the motor 45a is satisfied".
[0138] Step 340: The SP/CPU changes the position of any of the
control valves 46R, 46L, 47R and 47L corresponding to any of the
suspension devices 41 to 44 which does not complete the vehicle
height adjustment to the communication position. In addition, the
SP/CPU changes the position of the exhaust valve 48 to the shut-off
position when it is necessary to make any of the suspension devices
41 to 44 raise the corresponding wheel area vehicle height.
[0139] On the other hand, the SP/CPU changes the position of the
exhaust valve 48 to the communication position when it is necessary
to make any of the suspension devices 41 to 44 lower the
corresponding wheel area vehicle height.
[0140] Then, when a predetermined time period elapses, the SP/CPU
starts executing the processes from the step 300 again and executes
the processes of the step 305 and the steps following the step 305.
At the process of the step 310 being executed, the vehicle height
adjustment is not completed. Therefore, the SP/CPU judges "No" at
the step 310 and then, proceeds directly to the step 330. As a
result, the vehicle height adjustment is executed by executing the
processes of the steps 330 and 340.
[0141] Then, when the actual wheel area vehicle heights with
respect to all of the vehicle body parts (the parts of the vehicle
body corresponding to the wheels) correspond to a value adjacent to
the target vehicle height VHtgt (that is, correspond to a value
between the values VHL and VHU) for each of the wheel area vehicle
heights, the SP/CPU judges "No" at the step 330 and then, executes
the processes of the step 345 and 350 described below in sequence.
Then, the SP/CPU proceeds to the step 395 where the SP/CPU
terminates the routine.
[0142] Step 345: The SP/CPU stops driving the compressor driving
motor 45a if the motor 45a is being driven.
[0143] Step 350: The SP/CPU changes the position of any of the
control valves 46R, 46L, 47R and 47L, which has been controlled to
communication position, to the shut-off position. Further, the
SP/CPU changes the position of the exhaust valve 48 to the shut-off
position if the position of the exhaust valve 48 has been
positioned at the communication position.
[0144] Thereby, the vehicle height adjustment based on the
manipulation of the user switch 34 is completed.
[0145] In some cases, the vehicle body may be inclined by the
driver and/or the passenger getting in or out of the vehicle 10
when the vehicle 10 has been stopped or by the air leakage from any
of the chambers 41a to 44a. Accordingly, the SP/ECU 50 executes an
automatic leveling control for correcting the inclination of the
vehicle body.
[0146] That is, when the user switch 34 is not manipulated at the
process of the step 315 being executed, the SP/CPU judges "No" at
the step 315 and then, proceeds to the step 355 where the SP/CPU
judges if a requirement for correcting the inclination of the
vehicle body (an automatic leveling requirement) has been
generated. The SP/CPU generates the automatic leveling requirement
when the SP/CPU judges that the body of the vehicle 10 is inclined
on the basis of the output values of the vehicle height sensors 51
to 54, etc.
[0147] Now, it is assumed that the vehicle body is inclined and
thus, the automatic leveling requirement is generated. In this
case, the SP/CPU judges "Yes" at the step 355 and then, proceeds to
the step 360 where the SP/CPU judges if the target vehicle height
change allowance condition is satisfied. For example, this
condition is satisfied when the engine 20 is being operated and the
battery voltage VB is higher than or equal to the threshold voltage
VBth. It should be noted that the condition judged at the step 360
may be the same as or different from the condition judged at the
step 320.
[0148] When the target vehicle height change allowance condition is
satisfied at the process of the step 360 being executed, the SP/CPU
judges "Yes" at the step 360 and then, executes the processes of
the steps 325 and 330. Further, the SP/CPU executes the processes
of the step 335 and 340 until the vehicle height adjustment based
on the automatic leveling control is completed. Then, after the
vehicle height adjustment based on the automatic leveling control
is completed, the SP/CPU executes the processes of the step 345 and
350. As a result, the vehicle height adjustment is stopped and
thus, the vehicle body is maintained generally horizontal.
[0149] It should be noted that when the SP/CPU judges "No" at any
of the steps 305, 320, 355 and 360, the SP/CPU proceeds directly to
the step 395 where the SP/CPU terminates the routine. Therefore, in
this case, the vehicle height adjustment is not carried out and
thus, the motor 45a is not driven.
[0150] (2) Sending Stop Inhibition Request Signal and Limiting
Motor Drive
[0151] Further, the SP/CPU is programmed to execute a stop
inhibition requesting signal sending/motor driving limiting routine
shown in FIG. 4 by a flow chart every a predetermined time period
elapses. Therefore, the SP/CPU starts the processes from the step
400 of FIG. 4 at a predetermined timing and then, proceeds to the
step 410 where the SP/CPU judges if the compressor driving motor
45a is being driven.
[0152] When the motor 45 is not driven at the process of the step
410 being executed, the SP/CPU judges "No" at the step 410 and
then, proceeds directly to the step 460 where the SP/CPU stops
sending the stop inhibition request signal to the EG/ECU 30. It
should be noted that when the SP/ECU 50 does not send the stop
inhibition requesting signal to the EG/ECU 30 at the process of the
step 410 being executed, the process of the step 460 is executed
for confirming that the SP/ECU 50 does not send the stop inhibition
requesting signal to the EG/ECU 30.
[0153] On the other hand, when the motor 45a is being driven at the
process of the step 410 being executed, the SP/CPU judges "Yes" at
the step 410 and then, proceeds to the step 420 where the SP/CPU
judges if the motor 45a has been continued to be driven beyond the
threshold driving time period Tth.
[0154] If the vehicle height adjustment is normally carried out,
the vehicle height adjustment is completed at a timing before the
motor 45a has been continued to be driven beyond the threshold
driving time period Tth. Hereinafter, for convenience, the timing
when the time period of driving the motor 45a reaches the threshold
driving time period Tth may be referred to as "the second timing
when the time period of driving the motor 45a reaches a
predetermined constant time period Tth. Therefore, normally, the
motor 45a has not been continued to be driven beyond the threshold
driving time period Tth. Thereby, normally, the SP/CPU judges "No"
at the step 420 and then, proceeds to the step 470 where the SP/CPU
sends the stop inhibition requesting signal to the EG/ECU 30
through the onboard network CAN. Then, the SP/CPU proceeds to the
step 495 where the SP/CPU terminates the routine.
[0155] As described above, if the vehicle height adjustment is
normally carried out, the motor 45a has not been continued to be
driven beyond the threshold driving time period Tth. Therefore,
when the motor 45a has been continued to be driven beyond the
threshold driving time period Tth, it can be deemed that a
malfunction occurs during the vehicle height adjustment.
Accordingly, when the motor 45a has been continued to be driven
beyond the threshold driving time period Tth (that is, the second
timing described above has come) at the process of the step 420
being executed, the SP/CPU judges "Yes" at the step 420 and then,
executes the processes of the step 430 to 460 described below in
sequence. Then, the SP/CPU proceeds to the step 495 where the
SP/CPU terminates the routine.
[0156] Step 430: The SP/CPU sets "1" to the value of the vehicle
height adjustment stop flag Xteishi. As a result, until the state
of the ignition switch 32 is changed to the OFF state and then, to
the ON state, no vehicle height adjustment is carried out (refer to
the step 305 of FIG. 3).
[0157] Step 440: The SP/CPU stops driving the compressor driving
motor 45a.
[0158] Step 450: The SP/CPU changes the position of any of the
control valves 46R, 46L, 47R and 47L, which has been controlled to
the communication position, to the shut-off position. Further, if
the position of the exhaust valve 48 has been controlled to the
communication position, the SP/CPU changes the position of the
exhaust valve 48 to the shut-off position.
[0159] Step 460: The SP/CPU stops sending the stop inhibition
requesting signal to the EG/ECU 30.
2. Actuation of EG/ECU
(1) Resetting of Mask (Mask Flag)
[0160] The CPU of the EG/ECU 30 (the EG/CPU) is programmed to
execute a mask resetting routine shown in FIG. 5 by a flow chart
every a predetermined time period elapses. Therefore, the EG/CPU
starts the processes from the step 500 of FIG. 5 at a predetermined
timing and then, proceeds to the step 510 where the EG/CPU judges
if the present time is immediately after the state of the ignition
switch 32 is changed from the OFF state (the OFF position) to the
ON state (the ON position).
[0161] When the present time is immediately after the ignition
switch 32 is changed to the ON state, the EG/CPU judges "Yes" at
the step 510 and then, proceeds to the step 520 where the EG/CPU
sets "0" to the value of a mask flag Xmask (resets the mask flag
Xmask). Then, the EG/CPU proceeds to the step 595 where the EG/CPU
terminates the routine.
[0162] On the other hand, when the present time is not immediately
after the ignition switch 32 is changed to the ON state at the
process of the step 510 being executed, the EG/CPU judges "No" at
the step 510 and then, proceeds directly to the step 595 where the
EG/CPU terminates the routine. As described above, the mask flag
Xmask is reset immediately after the state of the ignition switch
32 is changed from the OFF state to the ON state.
(2) Seting of Mask (Mask Flag)
[0163] The EG/CPU is programmed to execute a mask setting routine
shown in FIG. 6 by a flow chart every a predetermined time period
elapses. Therefore, the EG/CPU starts the processes from the step
600 of FIG. 6 at a predetermined timing and then, proceeds to the
step 610 where the EG/CPU judges if the SP/ECU 50 has continued to
send the stop inhibition requesting signal to the EG/ECU 30 beyond
the malfunction judgment threshold time period Tijoth
(=Tth+.alpha.). That is, the EG/CPU judges if the stop inhibition
requesting singal has been continued to be sent to the EG/ECU 30
for the malfunction judgment threshold time period Tijoth.
[0164] As described above, if the SP/ECU 50 is under the normal
state, the driving of the motor 45a is stopped when the motor 45a
has been continued to be driven for the threshold driving time
period Tth. Thus, the stop inhibition requesting signal has not
been continued to be sent beyond the threshold driving time period
Tth (refer to the steps 420 and 470 of FIG. 4). Therefore, when the
SP/ECU 50 has continued to send the stop inhibition requesting
signal to the EG/ECU 30 beyond the malfunction judgment threshold
time period Tijoth, it can be judged that the malfunction occurs in
the SP/ECU 50. One of the reason of generating such a malfunction
is the thermal runaway of the SP/CPU.
[0165] Accordingly, when the SP/ECU 50 has continued to send the
stop inhibition requesting signal to the EG/ECU 30 beyond the
malfunction judgment threshold time period Tijoth, the EG/CPU
judges that the malfunction occurs in the SP/ECU 50 (that is, the
EG/CPU judges "Yes" at the step 610) and then, proceeds to the step
620. At the step 620, the EG/CPU sets "1" to the value of the mask
flag Xmask (that is, the EG/CPU sets the mask flag Xmask) and then,
proceeds to the step 695 where the EG/CPU terminates the
routine.
[0166] On the other hand, when the SP/ECU 50 has not continued to
send the stop inhibition requesting signal to the EG/ECU 30 beyond
the malfunction judgment threshold time period Tijoth at the
process of the step 610 being executed, the EG/CPU judges "No" at
the step 610 and then, proceeds directly to the step 695 where the
EG/CPU terminates the routine.
(3) Automatic Stop of Engine Operation
[0167] The EG/CPU is programmed to execute an automatic engine
operation stopping routine shown in FIG. 7 by a flow chart every a
predetermined time period elapses. Therefore, the EG/CPU starts the
processes from the step 700 of FIG. 7 at a predetermined timing and
then, proceeds to the step 710 where the EG/CPU judges if the
engine 20 is being operated. When the operation of the engine 20 is
stopped, the EG/CPU judges "No" at the step 710 and then, proceeds
directly to the step 795 where the EG/CPU terminates the
routine.
[0168] On the other hand, when the engine 20 is being operated at
the process of the step 710 being executed, the EG/CPU judges "Yes"
at the step 710 and then, proceeds to the step 720 where the EG/CPU
judges if the engine operation stop condition described above is
satisfied (refer to the conditions 1 to 3 described above).
[0169] When the engine operation stop condition is not satisfied,
the EG/CPU judges "No" at the step 720 and then, proceeds directly
to the step 750 where the EG/CPU contnues to operate the engine 20.
Then, the EG/CPU proceeds to the step 795 where the EG/CPU
terminates the routine.
[0170] On the other hand, when the engine operation stop condition
is satisfied at the process of the step 720 being executed, the
EG/CPU judges "Yes" at the step 720 and then, proceeds to the step
730 where the EG/CPU judges if the SP/ECU 50 sends the stop
inhibition requesting signal to the EG/ECU 30.
[0171] When the SP/ECU 50 does not send the stop inhibition
requesting signal to the EG/ECU 30, the EG/CPU judges "No" at the
step 730 and then, proceeds to the step 760 where the EG/CPU stops
the operation of the engine 20 by stopping the fuel injection and
the fuel ignition. Then, the EG/CPU proceeds to the step 795 where
the EG/CPU terminates the routine.
[0172] On the other hand, when the SP/ECU 50 sends the stop
inhibition requesting signal to the EG/ECU 30 at the process of the
step 730 being executed, the EG/CPU judges "Yes" at the step 730
and then, proceeds to the step 740 where the EG/CPU judges if the
value of the mask flag Xmask is "0". That is, the EG/CPU judges if
it is judged that the malfunction occurs in the SP/ECU 50 on the
basis of the value of the mask flag Xmask.
[0173] When the value of the mask flag Xmask is "0", that is, when
the EG/CPU does not judge that the malfunction occurs in the SP/ECU
50, the EG/CPU judges "Yes" at the step 740 and then, proceeds to
the step 750. At the step 750, the EG/CPU continues to operate the
engine 20 without automatically stopping the operation of the
engine 20 and then, proceeds to the step 795 where the EG/CPU
terminates the routine. That is, when the value of the mask flag
Xmask is "0", the stop inhibition requesting signal sent to the
EG/ECU 30 is deemed to be a normal signal and as a result, the
automatic stop of the operation of the engine 20 is inhibited
according to the stop inhibition requesting signal.
[0174] On the other hand, when the value of the mask flag Xmask is
"1" at the process of the step 740 being executed, that is, when
the EG/CPU judges that the malfunction occurs in the SP/ECU 50, the
EG/CPU judges "No" at the step 740 and then, proceeds to the step
760. At the step 760, the EG/CPU stops the operation of the engine
20 and then, proceeds to the step 795 where the EG/CPU terminates
the routine.
[0175] As described above, even when the engine operation stop
inhibition requesting signal is sent to the EG/ECU 30, if the
engine operation stop condition is satisfied and the value of the
mask flag Xmask is "1", the EG/CPU ignores (masks) the stop
inhibition requesting signal and automatically stops the operation
of the engine 20.
(4) Start of Engine Operation
[0176] The EG/CPU is programmed to execute an engine operation
starting routine shown in FIG. 8 by a flow chart every a
predetermined time period elapses. Therefore, the EG/CPU starts the
processes from the step 800 of FIG. 8 at a predetermined timing and
then, proceeds to the step 810 where the EG/CPU judges if the
operation of the engine 20 is being stopped (the operation of the
engine 20 was automatically stopped by the process of the step
760). When the operation of the engine 20 is not stopped, the
EG/CPU judges "No" at the step 810 and then, proceeds directly to
the step 895 where the EG/CPU terminates the routine.
[0177] On the other hand, when the operation of the engine 20 is
being stopped, the EG/CPU judges "Yes" at the step 810 and then,
proceeds to the step 820 where the EG/CPU judges if an engine
operation start condition is satisfied. For example, the engine
operation start condition is satisfied when all conditions
described below are satisfied. Of course, the other conditions may
be employed as the engine operation start condition.
[0178] (Condition 4) The brake switch is under the OFF state. That
is, the brake pedal is not depressed.
[0179] (Condition 5) The acceleration pedal manipulation amount AP
is larger than zero. That is, the acceleration pedal is depressed
and thus, the acceleration request is generated.
[0180] When the engine operation start condition is not satisfied
at the process of the step 820 being executed, the EG/CPU judges
"No" at the step 820 and then, proceeds directly to the step 895
where the EG/CPU terminates the routine.
[0181] On the other hand, when the engine operation start condition
is satisfied, the EG/CPU judges "Yes" at the step 820 and then,
proceeds to the step 830 where the EG/CPU starts the operation of
the engine 20. Then, the EG/CPU proceeds to the step 895 where the
EG/CPU terminates the routine.
[0182] As described above, the engine control device 30 according
to the embodiment described above is installed on the vehicle 10
equipped with the suspension control device 50 for driving the
electric actuator (the motor 45a) for changing the suspension
property (in the embodiment described above, the vehicle height) of
the vehicle 10.
[0183] The engine control device 30 has an engine control part (the
EG/CPU). The engine control part is programmed to automatically
stop the operation of the engine 20 when the predetermined engine
operation stop condition is satisfied (refer to the steps 220 and
260 of FIG. 2 and the steps 720 and 760 of FIG. 7). Further, the
engine control part is programmed to automatically start the
operation of the engine 20 when the predetermined engine operation
start condition is satisfied (refer to the steps 820 and 830 of
FIG. 8).
[0184] If the suspension control device 50 sends the stop
inhibition requesting signal for inhibiting the automatic stop of
the operation of the engine 20 in order to drive the actuators to
the engine control device 30, the engine control part is programmed
to continue to operate the engine 20 even when the engine operation
stop condition is satisfied (refer to the steps 220, 230 and 250 of
FIG. 2 and the steps 720, 730 and 750 of FIG. 7).
[0185] Further, the engine control part is programmed to:
[0186] judge if a malfunction occurs in the suspension control
device 50 (refer to the step 240 of FIG. 2, the steps 610 and 620
of FIG. 6 and the step 740 of FIG. 7); and
[0187] ignore the stop inhibition requesting signal and stop the
operation of the engine 20 when the engine control part judges that
the malfunction occurs in the suspension control device 50 (refer
to the judgment "Yes" at the step 240 of FIG. 2 and the judgment
"No" at the step 740 of FIG. 7), even if the engine operation stop
condition is satisfied and the stop inhibition requesting signal is
sent to the engine control device 30 (refer to the steps 220, 230,
240 and 260 of FIG. 2 and the steps 720, 730, 740 and 760 of FIG.
7).
[0188] Therefore, even when the stop inhibition requesting signal
is continued to be sent to the engine control device 30 due the
malfunction of the suspension control device 50, the operation of
the engine 20 can be stopped when the engine operation stop
condition is satisfied. As a result, the increasing of the
consumption of the fuel can be prevented.
[0189] Further, the engine control part is programmed to judge if a
malfunction occurs in the suspension control device 50 by using the
stop inhibition requesting signal (refer to FIG. 6).
[0190] Furthermore, the suspension control device 50 is configured
to:
[0191] drive the actuator (the motor 45a) during a particular time
period (during a time period between the timing when the driving of
the motor 45a for the vehicle height adjustment starts and the
second timing when the threshold driving time period Tth elapses);
and
[0192] send the stop inhibition requesting signal to the engine
control device 30 while the suspension control device 50 drives the
actuator (the motor 45a) (refer to the step 335 of FIG. 3 and the
step 470 of FIG. 4).
[0193] Furthermore, the engine control part is programmed to judge
that the malfunction occurs in the suspension control device 50
when the stop inhibition requesting signal is sent to the engine
control device 30 during a time period other than the particular
time period (refer to the step 240 of FIG. 2 and FIG. 6).
[0194] In particular, the suspension control device 50 is
configured to: start driving the motor 45a at the first timing when
the condition of driving the motor 45a is satisfied and stop
driving the motor 45a at the second timing when the time period of
driving the motor 45a reaches the predetermined constant time
period (the threshold driving time period Tth) or at the timing
before the second timing (refer to the judgemnet "No" at the step
410 and the step 460 of FIG. 4 and the judgments "Yes" at steps 410
and 420 of FIG. 4 and the steps 430 to 460 of FIG. 4); and
[0195] send the stop inhibition requesting signal to the engine
control device 30 while the suspension control device 30 drives the
motor 45a (refer to the step 335 of FIG. 3 and the steps 410, 420
and 470 of FIG. 4).
[0196] Further, the engine control part is programmed to judge that
the malfunction occurs in the suspension control device 50 when the
suspension control device 50 has continued to send the stop
inhibition requesting signal to the engine control device 30 for a
threshold time period (the malfunction judgment threshold time
period Tijoth) beyond the predetermined constant time period (the
threshold driving time period Tth) (refer to the step 240 of FIG. 2
and FIG. 6).
[0197] Further, the engine control part is programmed to continue
to ignore the stop inhibition requesting signal until the state of
the ignition switch 32 of the vehicle 10 is changed from the ON
state to the OFF state when the engine control part judges that the
malfunction occurs in the suspension control device 50 (refer to
the fact that "1" is continued to be set to the mask flag Xmask in
FIGS. 5 and 6 and the mask flag Xmask is referred at the step 740
in FIG. 7).
[0198] Furthermore, the engine control part is programmed to stop
ignoring the stop inhibition requesting signal when the state of
the ignition switch 32 is changed from the ON state to the OFF
state and then, again to the ON state after the engine control part
judges that the malfunction occurs in the suspension control device
50 (refer to the fact that the "0" is set to the mask flag Xmask in
FIG. 5 and the mask flag Xmask is referred at the step 740 of FIG.
7).
[0199] Therefore, the engine control device 30 according to the
embodiment described above can avoid that the engine 20 is
continued to be operated due to the occurrence of the malfunction
in the suspension control device 50 when the condition of stopping
the operation of the engine 20 is satisfied. As a result, the
engine control device 30 can avoid the increasing of the fuel
consumption of the engine 20.
<Modifications>
[0200] Next, modifications of the embodiment described above will
be described. The modification described below is the same as the
embodiment described above except that the EG/CPU is programmed to
execute a mask setting routine shown in FIG.9 in place of the mask
setting routine shown in FIG. 6. Therefore, the difference between
the modification and the embodiment described above will be mainly
described.
[0201] The EG/CPU is programmed to execute the mask setting routine
shown in FIG.9 by a flow chart every a predetermined time period
elapses. Therefore, the EG/CPU starts the processes from the step
900 of FIG.9 at a predeteremined timing and then, proceeds to the
step 910 where the EG/CPU judges if a state where the vehicle speed
SPD is lower than or equal to the engine operation stop threshold
vehicle speed SPDth and the SP/ECU 50 sends the engine operation
stop inhibition requesting signal to the EG/ECU 30 (hereinafter,
this state will be referred to as "the first state") has continued
beyond the malfunction judgment threshold time period Tijoth
(=Tth+.alpha.).
[0202] When the first state has continued beyond the malfunction
judgment threshold time period Tijoth, the EG/CPU judges that the
malfunction occurs in the SP/ECU 50 (that is, the EG/CPU judges
"Yes" at the step 910) and then, proceeds to the step 920. At the
step 920, the EG/CPU sets "1" to the value of the mask flag Xmask
(that is, the EG/CPU sets the mask flag Xmask) and then, proceeds
to the step 995 where the EG/CPU terminates the routine.
[0203] On the other hand, when the first state has not continued
beyond the malfunction judgment threshold time period Tijoth at the
process of the step 910 being executed, the EG/CPU judges "No" at
the step 910 and then, proceeds directly to the step 995 where the
EG/CPU terminates the routine.
[0204] As described above, the modification judges that the
malfunction occurs in the SP/ECU 50 when the first state has
continued beyond the malfunction judgment threshold time period
Tijoth. Therefore, it can be said that this modification judges
that the malfunction occurs in the SP/ECU 50 when the SP/ECU 50 has
continued to send the stop inhibition requesting signal to the
EG/ECU 30 beyond the malfunction judgment threshold time period
Tijoth similar to the embodiment described above.
[0205] As described above, according to the embodiment and the
modification, even when the malfunction (including a malfunction of
the communication using the onboard network) occurs in the SP/ECU
50 and the signal for inhibiting the automatic stop of the
operation of the engine 20 (the stop inhibition requesting signal)
has been continued to be generated, the operation of the engine 20
can be automatically stopped. Thereby, the running of the vehicle
10 with the increased consumption of the fuel of the engine 20, can
be avoided.
[0206] It should be noted that the invention is not limited to the
embodiment described above and various modifications can be
employed within the scope of the invention. For example, the EG/ECU
30 according to the embodiment described above judges if a
malfunction occurs in the SP/ECU 50 by using the stop inhibition
requesting signal. However, it may be judged if a malfunction
occurs in the SP/ECU 50 by the other method.
[0207] In particular, the SP/ECU 50 may be programmed to send a
pulse signal having a particular pattern through the CAN to the
EG/ECU 30 every a constant time period elapses. In this case, the
EG/ECU 30 may be programmed to judge that the malfunction occurs in
the SP/ECU 50 when the pulse signal is not sent to the EG/ECU 30
every the constant time period elapses.
[0208] Further, according to the embodiment described above, the
actuator, which is driven when the stop inhibition requesting
signal is generated, is the motor 45a. However, the actuator is not
limited to the motor 45a. For example, when each of the absorber
control actuators 41c to 44c needs a large power or a large voltage
for ensuring the operation of the actuator, the SP/ECU 50 may be
programmed to send the stop inhibition request signal to the EG/ECU
50 when the SP/ECU 50 drives such actuators. However, even in this
case, it is preferred that the time period for continuously driving
the actuators is limited to a time period shorter than the
threshold driving time period Tth.
[0209] Further, the SP/ECU 50 may be programmed to always drive the
motor 45a from the timing when the motor driving condition is
satisfied to the timing when the constant time period TA elapses.
In this case, the particular time period corresponds to a time
period from the timing when the motor driving condition is
satisfied to the timing when the constant time period TA elapses
and the SP/ECU 50 continues to send the stop inhibition requesting
signal to the EG/ECU 30 during the particular time period TA.
[0210] Therefore, in this case, the EG/ECU 30 may be programmed to:
deem the time period from the timing when the EG/ECU starts
receiving the stop inhibition requesting signal to the timing when
the constant time period TA elapses as the particular time period;
and
[0211] judge that the malfunction occurs in the SP/ECU 50 when the
EG/ECU 30 receives the stop inhibition requesting signal during a
time period other than the particular time period.
[0212] Alternatively, if the EG/ECU 30 and the SP/ECU 40 can
identify a certain time period (that is, the particular time
period) separately (that is, without the information exchange by
the communication) and the SP/ECU 50 is programmed to drive the
actuator during the particular time period and send the stop
inhibition requesting signal to the EG/ECU 30, the EG/ECU 30 may be
programmed to judge that the malfunction occurs in the SP/ECU 50
when the EG/ECU 30 receives the stop inhibition requesting signal
during a time period other than the particular time period.
Further, the EG/ECU may be connected to the vehicle speed sensor 33
and detect the vehicle speed SPD directly or may be programmed to
acquire the vehicle speed SPD from the other ECU not shown (for
example, a meter ECU) through the CAN.
* * * * *